Medical devices, such as implantable medical devices, may be used to deliver electrical stimulation therapy to patients to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, epilepsy, incontinence, or gastroparesis. Electrical stimulation therapy may be applied to deliver stimulation to any of a variety of tissue sites and may comprise neurostimulation, or possibly stimulation of muscle tissue or the like. A medical device may deliver electrical stimulation therapy via a stimulator generator and one or more implantable leads that include electrodes located proximate to the spinal cord, pelvic nerves, or stomach, or within the brain of a patient. The stimulation generator may be external or implantable. For chronic therapy, an implantable stimulation generator is ordinarily desirable. In general, the medical device delivers electrical stimulation therapy in the form of electrical pulses, although continuous waveforms alternatively or additionally may be applied.
Drug pumps, such as implantable drug pumps, are another type of implantable medical device that can be used to treat patients. Drug pumps typically include a reservoir of agents that are delivered to a target site in a controlled manner via one or more implanted catheter. In some cases, electrical stimulation may be used in conjunction with drug therapy.
For electrical stimulation, a clinician, such as a physician or other medical staff, may surgically implant the leads to properly position electrodes at one or more implantation sites desirable for stimulation therapy. The clinician may also select values for a number of programmable parameters in order to define the electrical stimulation therapy to be delivered to a patient. For example, the clinician may select an amplitude, which may be a current or voltage amplitude, and a pulse width for a stimulation waveform to be delivered to the patient, as well as a rate at which the pulses are to be delivered to the patient. The clinician may select, as additional parameters, the particular electrodes within an electrode set to be used to deliver the pulses, and the polarities of the selected electrodes. In some cases, non-pulsed waveforms may be used to drive the stimulation. In any case, a group of parameter values may be referred to as a program in the sense that they drive the electrical stimulation therapy to be delivered to the patient.
For pain treatment, conventional techniques for implantation and configuration of the implantable medical devices may rely on patient feedback. In many cases, however, patient feedback may be an inaccurate or time consuming measure of the accuracy of the electrode placement and/or the configuration of the stimulation parameters of an implantable electrical stimulation device.